The present invention concerns a fan-shaped diffuser for atomizers or mist blowers of treatment liquids in agriculture.
There are already known to be various types of mist blowers or atomizers for treatment liquids to be sprayed on any kind of cultivation (such as fruit trees, vineyards, vegetables, strawberry cultivations, and the like), mounted on wheels to be drawn along the fields, or without wheels and carried through the fields by farm tractors. Among said mist blowers or atomizers, the ones using the so called "low volume" system have successfully developed due to their advantageous characteristics. In such atomizers or mist blowers: on one hand, air is fed at high pressure into a large tube ending into a short narrow duct, where the air blows at a very high speed; on the other hand, said treatment liquid is caused to flow at very low pressure towards delivery holes provided into said narrow duct. In various accomplishments of the Applicant, said narrow duct has the characteristics of a real diffuser, acting as a Venturi tube in order to spray the treatment liquid in tiny drops, with the most rational use of said liquid and thereby avoiding any waste thereof.
There are many practical accomplishments of said diffusers, but the ones produced by the Applicant which have proved to be particularly efficient are the diffusers in which the distribution of the treatment liquid is obtained by placing into the narrow duct, wherein air flows at high speed, a small copper tube having aligned, gauged and equidistant holes on its surface. In some of said diffusers, the narrow duct is fan-shaped and the small tube is placed along its fan-shaped opening.
This arrangement has however proved to involve two serious drawbacks: the first one due to the fact that, especially in certain working positions of the diffuser, the liquid tends to spread in said tube in a scarcely uniform manner and is thus distributed in a fully irregular way through the various gauged holes; the second one due to the fact that said holes tend to become wider, especially with some treatment liquids having corrosive properties, they prevent a correct spraying action and thus comprise the proper working of the mist blower.